JP2014180011A - Determination of radio link failure with enhanced interference coordination and cancellation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine radio link failure (RLF) by analysis with RLF conditions taking into account cooperative resource coordination between cells.SOLUTION: UE 604 is configured to: detect interference from an interfering base station (femto base station) 602 in a network (macro cell) 601 supporting an interference coordination and cancellation mechanism that includes yielding of a wireless transmission resource and assignment of the yielded wireless transmission resource from the interfering base station 602 to a serving base station (macro base station) 600; receive a dedicated message identifying the yielded resource from the interfering base station 602; determine signal quality of the yielded resource; and declare a radio link failure when the determined signal quality meets a predetermined threshold value.

Description

Cross-reference to related applications

  This application is a US provisional patent entitled DETERMINATION OF RADIO LINK FAILURE WITH ENHANCED INTERFERENCE COORDINATION AND CANCELLATION, filed April 13, 2010, with enhanced interference coordination and cancellation. 35 U.S. for application 61 / 323,856. S. C. Insist on profit under §119 (e). The contents of this application are hereby incorporated by reference in their entirety for all purposes.

  Certain aspects of the present disclosure relate generally to wireless communication systems and, more particularly, to determining radio link failure in a system with enhanced interference coordination and cancellation.

  Wireless communication networks have been widely developed to provide various communication services such as voice, video, packet data, messaging, broadcast, and the like. These wireless networks can be multiple access networks that can support multiple users by sharing available network resources. Examples of such multiple access networks include code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, and single carrier FDMA ( SC-FDMA) network.

  A wireless communication network may include a number of base stations that can support communication for a number of user equipments (UEs). A UE may communicate with a base station via downlink and uplink. The downlink (ie, forward link) refers to the communication link from the base station to the UE, and the uplink (ie, reverse link) refers to the communication link from the UE to the base station.

  A base station may transmit data and control information to the UE on the downlink and / or receive data and control information from the UE on the uplink. On the downlink, transmissions from base stations may encounter interference due to transmissions from neighboring base stations or from other radio radio frequency (RF) transmitters. On the uplink, transmissions from the UE may encounter interference from another UE's uplink transmissions communicating with neighboring base stations or from another wireless RF transmitter. This interference can degrade both downlink and uplink performance.

  As the demand for mobile broadband access continues to increase, the possibility of interference and congested networks increases as UEs access long-range wireless communication networks and short-range wireless systems are deployed in the community. Research and development continues to evolve UMTS technology not only to meet the increasing demand for mobile broadband access, but also to evolve and enhance the user experience with mobile communications.

  Existing criteria for analyzing radio link failure conditions may not be able to satisfactorily address conditions between cells that support coordinated resource coordination. In general, when the UE declares a radio link failure, the UE disconnects from the serving base station and searches for a new base station. If the UE is in a region of severe interference where the interference is coordinated between base stations by the interfering cell that gives up part of the resource, the UE measurement to determine radio link failure (RLF) is: Depending on whether the measured resource is abandoned by the interfering cell, it can vary considerably. If the UE measures a resource that is not abandoned by the interfering cell, the UE may still be able to access the serving cell using the resource abandoned by the interfering cell, but the UE (e.g., due to high interference) ) May declare RLF incorrectly. Accordingly, an aspect of determining RLF based on considering coordinated resource adjustment to apply abandoned resources is disclosed.

  In one aspect, a method for wireless communication is disclosed. In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of at least one abandoned resource from an interfering base station to a serving base station. Detecting interference from the base station of the interference source. A message identifying the abandoned resource is received from the interfering base station. In one aspect, the received message is a dedicated message. In another aspect, the received message may be a broadcast message and / or an overhead message. The signal quality of the abandoned resource is determined, and if the determined signal quality meets a predetermined threshold, a radio link failure is declared.

  Another aspect discloses a system for wireless communication having a memory and at least one processor coupled to the memory. The processor (s) support an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of at least one abandoned resource from the interfering base station to the serving base station In the network to detect interference from the base station of the interference source. The processor receives a dedicated message identifying the abandoned resource from the interfering base station. In another aspect, the processor receives a broadcast message and / or an overhead message that identifies the abandoned resource. The processor determines the signal quality of the abandoned resource and a radio link failure is declared if the determined signal quality satisfies a predetermined threshold.

  In another embodiment, a computer program product for wireless communication in a wireless network is disclosed. The computer-readable medium, when executed by one or more processors, causes the processor (s) to abandon at least one radio transmission resource and interfere with at least one abandoned resource. In a network that supports interference coordination and cancellation mechanisms including allocation from a base station to a serving base station, it has recorded program code for performing operations to detect interference from the interfering base station. The program code also causes one or more processors to receive a dedicated message identifying the abandoned resource from the interfering base station. In another aspect, the program code causes the processor to receive a broadcast message and / or an overhead message that identifies the abandoned message. The program code also causes one or more processors to determine the signal quality of the abandoned resource, and if the determined signal quality meets a predetermined threshold, the radio link Declare failure.

  Another aspect is in a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and assignment of at least one abandoned resource from an interfering base station to a serving base station. An apparatus including means for detecting interference from an interfering base station is disclosed. Means are also included for receiving a message identifying the abandoned resource from the interfering base station. In one aspect, the received message is a dedicated message. In another aspect, the received message may be a broadcast message and / or an overhead message. The apparatus includes means for determining the signal quality of an abandoned resource, and means for declaring a radio link failure if the determined signal quality satisfies a predetermined threshold.

  Additional features and advantages of the disclosure will be described below. It should be understood by those skilled in the art that the present disclosure can be readily utilized as a basis for modifying and designing other configurations to accomplish the same purpose as that of the present disclosure. It should also be understood by those skilled in the art that such equivalent constructions do not depart from the teachings of the disclosure recited in the claims. The novel features believed to be features of the present disclosure, both in terms of method of operation and configuration, as well as further objects and advantages, will be better understood from the following description when considered in conjunction with the accompanying drawings. Will be understood. However, it should be clearly understood that each drawing is provided for purposes of illustration and description only and is not intended as a definition of the limits of the present disclosure.

The features, characteristics and advantages of the present disclosure will become more apparent from the detailed description set forth below when considered in conjunction with the drawings, in which like reference characters identify like objects throughout.
FIG. 1 is a block diagram conceptually illustrating an example of a telecommunications system. FIG. 2 is a diagram conceptually illustrating an example of a downlink frame structure in a telecommunications system. FIG. 3 is a block diagram conceptually illustrating an example of a frame structure in uplink communication. FIG. 4 is a block diagram conceptually illustrating a design of a base station / eNode B and a UE configured in accordance with one aspect of the present disclosure. FIG. 5 is a block diagram conceptually illustrating adaptive resource partitioning in a heterogeneous network according to aspects of this disclosure. FIG. 6 is a diagram conceptually illustrating a macro cell in an LTE wireless network. FIG. 7 is a block diagram illustrating a method for determining radio link failure in a wireless network.

  The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be implemented. This detailed description includes specific details that are intended to provide a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts can be implemented without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

  The techniques described herein include, for example, code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal frequency division multiple access (OFDMA) networks, single It can be used for various wireless communication networks such as carrier FDMA (SC-FDMA) networks. The terms “network” and “system” are often used interchangeably. A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRA includes wideband CDMA (W-CDMA®) and low chip rate (LCR). CDMA2000 covers IS-2000, IS-95, and IS-856 standards. A TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA network may implement radio technologies such as Evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, Flash-OFDM®, and the like. UTRA, E-UTRA, and GSM are part of the Universal Mobile Telecommunication System (UMTS). Long Term Evolution (LTE) is the latest release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS, and LTE are described in documents from an organization named “3rd Generation Partnership Project” (3GPP). CDMA2000 is described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). These various radio technologies and standards are known in the art. For clarity, certain aspects of these techniques are described below for LTE, and LTE terminology is used in much of the description below.

  The techniques described herein may be used for various wireless communication networks such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other networks. The terms “network” and “system” are often used interchangeably. A CDMA network may implement radio technologies such as Universal Terrestrial Radio Access (UTRA), Telecommunications Industry Association (TIA) cdma2000®, and the like. UTRA technology includes wideband CDMA (WCDMA) and other variants of CDMA. CDMA2000® technology includes IS-2000, IS-95, and IS-856 standards from the Electronic Industries Association (EIA) and TIA.

  A TDMA network can implement a radio technology such as Global System for Mobile Communications (GSM). OFDMA networks include, for example, Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM ( Realize radio technology such as registered trademark. UTRA technology and E-UTRA technology are part of the Universal Mobile Telecommunication System (UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are new releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization called “3rd Generation Partnership Project” (3GPP). CDMA2000, cdma2000 and UMB are described in documents from an organization called “3rd Generation Partnership Project 2” (3GPP2). The techniques described herein may be used for the wireless networks and radio access technologies described above as well as other wireless networks and radio access technologies. For clarity, certain aspects of these techniques are described below for LTE or LTE-A (alternatively, they are both referred to as "LTE / -A"), and such LTE-A Terminology is used in much of the description below.

  FIG. 1 shows a wireless communication network 100 that may be an LTE-A network. The wireless network 100 includes a number of evolved Node B (eNode B) 110 and other network entities. The eNode B is a station that communicates with the UE, and may also be referred to as a base station, a Node B, an access point, or the like. Each eNodeB 110 provides communication coverage for a specific geographic area. In 3GPP, the term “cell” refers to this particular geographical area of eNodeBs and / or eNodeB subsystems serving this coverage area, depending on the context in which the term is used. It may refer to the effective communication range area.

  An eNodeB may provide communication coverage for macro cells, pico cells, femto cells, and / or other types of cells. A macro cell generally covers a relatively large geographic area (eg, a few kilometers in radius) and may allow unrestricted access by UEs with service subscriptions to network providers. A pico cell generally covers a relatively small geographic area and may allow unrestricted access by UEs with service subscriptions to network providers. A femto cell also typically covers a relatively small geographic area (eg, a residence) and is associated with a femto cell (eg, a UE in a closed subscriber group (CSG)), a user in a residence Unrestricted access by a UE or the like. An eNodeB for a macro cell may be referred to as a macro eNodeB. An eNodeB for a pico cell may be referred to as a pico eNodeB. An eNodeB for a femto cell may then be referred to as a femto eNodeB or a home eNodeB. In the example shown in FIG. 1, eNode Bs 110a, 110b, and 110c may be macro eNode Bs for macro cells 102a, 102b, and 102c, respectively. The eNodeB 110x may be a pico eNodeB for the pico cell 102x. The eNode Bs 110y and 110z are femto eNodeBs for the femto cells 102y and 102z, respectively. An eNodeB may support one or multiple (eg, 2, 3, 4, etc.) cells.

  The wireless network 100 may further include a relay station. The relay station receives data and / or other information transmissions from upstream stations (eg, eNodeB, UE, etc.) and relays data and / or other information transmissions to downstream stations (eg, UE or eNodeB). ). A relay station may also be a UE that relays transmissions for other UEs. In the example shown in FIG. 1, relay station 110r may communicate with eNode B 110a and UE 120r to facilitate communication between eNode B 110a and UE 120r. A relay station may also be referred to as a relay eNodeB, a relay, etc.

  The wireless network 100 may also be a heterogeneous network including different types of eNodeBs, such as, for example, a macro eNodeB, a pico eNodeB, a femto eNodeB, a relay, and the like. These different types of eNodeBs may have different transmission power levels, different coverage areas, and different impacts on interference within the wireless network 100. For example, a macro eNodeB may have a high transmit power level (eg, 20 watts), while a pico eNodeB, a femto eNodeB, and a relay may have a low transmit power level (eg, 1 watt). .

  The wireless network 100 supports synchronous operation. For synchronous operation, eNodeBs have similar frame timing, and transmissions from different eNodeBs can be approximately aligned in time. For asynchronous operation, eNodeBs have different frame timings, and transmissions from different eNodeBs may not be aligned in time. The techniques described herein can be used for either synchronous or asynchronous operation. In one aspect, the wireless network 100 may support a frequency division multiplexing (FDD) mode of operation or a time division multiplexing (TDD) mode of operation. The techniques described herein may be used for either the FDD mode of operation or the TDD mode of operation.

  Network controller 130 is connected to a set of eNodeBs 110 and may provide coordination and control for these eNodeBs 110. Network controller 130 may communicate with eNodeB 110 via the backhaul. The eNodeBs 110 may also communicate with each other, for example, directly or non-directly via a wireless or wired backhaul.

  UEs 120 may be distributed throughout the wireless network 100. Each UE can be fixed or mobile. A UE may also be referred to as a terminal, mobile station, subscriber unit, station, etc. A UE may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, and so on. A UE may be able to communicate with a macro eNodeB, a pico eNodeB, a femto eNodeB, a relay, and the like. In FIG. 1, a solid line with two arrows is the desired transmission between a UE and a serving eNodeB, which is an eNodeB designated to serve the UE on the downlink and / or uplink. Indicates. A broken line with two arrows indicates an interference transmission between the UE and the eNodeB.

  LTE utilizes frequency division multiplexing (OFDM) on the downlink and single carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, also commonly referred to as tones, bins, etc. Each subcarrier may be modulated with data. In general, modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers is fixed, and the total number of subcarriers (K) can depend on the system bandwidth. For example, the subcarrier spacing may be 15 kHz. And the minimum resource allocation (referred to as a “resource block”) may be 12 subcarriers (or 180 kHz). As a result, the nominal FFT size can be equal to 128, 256, 512, 1024, 2048, respectively, for the corresponding system bandwidth of 1.25, 2.5, 5, 10, 20 megahertz (MHz). The system bandwidth can also be partitioned into sub-bands. For example, the sub-band covers 1.08 MHz (ie, 6 resource blocks) and 1, 2, 4, 8, for corresponding system bandwidths of 1.25, 2.5, 5, 10, and 20 MHz, respectively. There may be 16 subbands.

  FIG. 2 shows a downlink FDD structure used in LTE. The downlink transmission timeline can be divided into units of radio frames. Each radio frame may be partitioned into 10 subframes having a predetermined duration (eg, 10 milliseconds (ms)) and indexed from 0 to 9. Each subframe may include two slots. Thus, each radio frame may include 20 slots indexed from 0-19. Each slot contains L symbol periods, seven symbol periods for a normal cyclic prefix (eg, as shown in FIG. 2), and 14 for an extended cyclic prefix. Symbol periods. In each subframe, 2L symbol periods may be assigned an index from 0 to 2L-1. Available time frequency resources may be partitioned into resource blocks. Each resource block may cover N subcarriers (eg, 12 subcarriers) in one slot.

  In LTE, an eNodeB may transmit a primary synchronization signal (PSC or PSS) and a secondary synchronization signal (SSC or SSS) for each cell at the eNodeB. In the FDD operation mode, as shown in FIG. 2, the primary synchronization signal and the secondary synchronization signal are symbol periods in each of subframe 0 and subframe 5 of each radio frame having a normal cyclic prefix. 6 and symbol period 5 may be transmitted respectively. These synchronization signals can be used by the UE for cell detection and acquisition. In the FDD mode of operation, the eNodeB may transmit a physical broadcast channel (PBCH) in symbol periods 0 to 3 in slot 1 of subframe 0. The PBCH can transmit certain system information.

  As seen in FIG. 2, the eNodeB may transmit a physical control format indicator channel (PCFICH) in the first symbol period of each subframe. PCFICH may convey the number of symbol periods (M) used for the control channel. Here, M is equal to 1, 2 or 3, and may change every subframe. M can also be equal to 4 for a small number of system bandwidths, eg, less than 10 resource blocks. In the example shown in FIG. 2, M = 3. The eNodeB may transmit a physical HARQ indicator channel (PHICH) and a physical downlink control channel (PDCCH) in the first M symbol periods of each subframe. PDCCH and PHICH are also included in the first three symbol periods in the example shown in FIG. The PHICH may carry information to support hybrid automatic retransmission (HARQ). The PDCCH may carry information regarding uplink and downlink resource allocation for the UE and power control information for the uplink channel. The eNodeB may also transmit a physical downlink shared channel (PDSCH) in the remaining symbol periods of each subframe. The PDSCH may transmit data for UEs scheduled for data transmission on the downlink.

  The eNodeB may transmit PSC, SSS, and PBCH at the central 1.08 MHz of system bandwidth used by the eNodeB. The eNodeB may transmit PCFICH and PHICH over the entire system bandwidth in each symbol period during which these channels are transmitted. An eNodeB may transmit a PDCCH to a group of UEs in some part of the system bandwidth. The eNodeB may send a PDSCH to a group of UEs in a specific part of the system bandwidth. The eNodeB may transmit PSC, SSC, PBCH, PCFICH, and PHICH to all UEs in a broadcast manner, and may transmit PDCCH to a specific UE in a unicast manner. Furthermore, PDSCH can be transmitted to a specific UE in a unicast manner.

  Many resource elements may be available in each symbol period. Each resource element covers one subcarrier in one symbol period and can be used to transmit one modulation symbol that is real-valued or complex-valued. For symbols used for the control channel, resource elements that are not used for the reference signal in each symbol period may be configured into a resource element group (REG). Each REG may include four resource elements within one symbol period. PCFICH can occupy four REGs in symbol period 0. They can be arranged at approximately equal intervals across the frequency. The PHICH can occupy three REGs within one or more configurable symbol periods. These can be distributed over frequency. For example, all three REGs for PHICH may belong to symbol period 0. Alternatively, it can be distributed over symbol periods 0, 1, and 2. The PDCCH may occupy 9, 18, 36, or 72 REGs within the first M symbol periods. These can be selected from available REGs. Only certain combinations of multiple REGs may be allowed for PDCCH.

  The UE may recognize a specific REG used for PHICH and PCFICH. The UE may search for different combinations of REGs for PDCCH. The number of combinations to search is generally less than the number of combinations allowed for all UEs on the PDCCH. The eNodeB may transmit the PDCCH to any UE of the combinations that the UE searches for.

  A UE may be within the effective communication range of multiple eNodeBs. One of these eNodeBs may be selected to serve the UE. The serving eNodeB may be selected based on various criteria such as received power, path loss, signal to noise ratio (SNR), and the like.

  FIG. 3 is a block diagram conceptually illustrating a typical FDD and TDD (non-special subframe only) subframe structure in uplink long term evolution (LTE) communication. A resource block (RB) available for the uplink may be partitioned into a data section and a control section. The control section is formed at two ends of the system bandwidth and may have a configurable size. Resource blocks in the control section may be allocated to the UE for transmission of control information. The data section may include all resource blocks that are not included in the control section. As a result of the design in FIG. 3, the data section includes consecutive subcarriers. This allows a single UE to be assigned all of the consecutive subcarriers in the data section.

  The UE may be assigned resource blocks in the control section to send control information to the eNodeB. The UE may also be assigned resource blocks in the data section for transmitting data to the eNodeB. The UE may send control information on a physical uplink control channel (PUCCH) with resource blocks allocated in the control section. A UE may transmit data alone or both data and control information on a physical uplink shared channel (PUSCH) with resource blocks allocated in the data section. The uplink transmission spans both slots of subframes and can hop across the frequency as shown in FIG. According to one aspect, parallel channels can be transmitted with UL resources in relaxed single carrier operation. For example, a control and data channel, a parallel control channel, and a parallel data channel can be transmitted by the UE.

  FIG. 4 shows a block diagram of a design of a base station / eNode B 110 and a UE 120, which may be one of the base stations / e Node Bs in FIG. 1 and one of the UEs. For the constrained relevance scenario, the base station 110 may be the macro eNode B 110c in FIG. And UE120 may be UE120y. Base station 110 can also be several other types of base stations. The base station 110 may include antennas 434a to 434t, and the UE 120 may include antennas 452a to 452r.

  At base station 110, transmit processor 420 may receive data from data source 412 and control information from controller / processor 440. The control information can be for PBCH, PCFICH, PHICH, PDCCH, and the like. The data can be for PDSCH or the like. Processor 420 may process (eg, encode and symbol map) the data information and control information to obtain data symbols and control symbols, respectively. The processor 420 may further generate, for example, reference symbols for PSS, SSS and cell-specific reference signals. A transmit (TX) multiple-input multiple-output (MIMO) processor 430 performs spatial processing (eg, precoding) on the reference symbols, control symbols, and / or data symbols, if applicable, Streams may be provided to modulators (MODs) 432a through 432t. Each modulator 432 processes a respective output symbol stream (eg, for OFDM, etc.) to obtain an output sample stream. Each modulator 432 further processes (eg, analog converts, amplifies, filters, and upconverts) the output sample stream to obtain a downlink signal. Downlink signals from modulators 432a through 432t may be transmitted by antennas 434a through 434t, respectively.

  In UE 120, antennas 452a through 452r may receive the downlink signals from base station 110 and provide the received signals to demodulators (DEMOD) 454a through 454r, respectively. Each demodulator 454 may condition (eg, filter, amplify, downconvert, and digitize) each received signal to obtain input samples. Each demodulator 454 may further process these input samples (eg, for OFDM, etc.) to obtain received symbols. A MIMO detector 456 may obtain symbols received from all demodulators 454a through 454r and, if applicable, perform MIMO detection on these received symbols and provide detected symbols. Receive processor 458 processes (eg, demodulates, deinterleaves, and decodes) the detected symbols, provides decoded data for UE 120 to data sink 460, and provides decoded control information to the controller / processor. 480 can be provided.

  On the uplink, at UE 120, transmit processor 464 may receive and process data (eg, for PUSCH) from data source 462 and control information (eg, for PUCCH) from controller / processor 480. . The processor 464 may also generate a reference symbol for the reference signal. Symbols from transmit processor 464 are precoded by TX MIMO processor 466, if applicable, and further processed by modulators 454a-454r (eg, for SC-FDM, etc.) and transmitted to base station 110. Is done. At base station 110, the uplink signal from UE 120 is received by antenna 434, processed by demodulator 432, detected by MIMO detector 436 when applicable, and further processed by receive processor 438, The decoded data and control information transmitted by the UE 120 is obtained. The processor 438 may provide decoded data to the data sink 439 and provide decoded control information to the controller / processor 440. The base station 110 can transmit a message to another base station via the X2 interface 441, for example.

  Controllers / processors 440 and 480 may direct the operation at base station 110 and UE 120, respectively. Processor 440 and / or other processors and modules at base station 110 may perform or direct the execution of various processes for the techniques described herein. Processor 480 and / or other processors and modules at UE 120 may perform or direct execution of the functional blocks illustrated in FIG. 7 and / or other processing for the techniques described herein. . Memories 442 and 482 may store data and program codes for base station 110 and UE 120, respectively. A scheduler 444 may schedule UEs for data transmission on the downlink and / or uplink.

  FIG. 5 is a block diagram illustrating TDM partitioning in a heterogeneous network according to one aspect of the present disclosure. The first row of the block illustrates subframe allocation for femto eNodeB, and the second row of the block illustrates subframe allocation for macro eNodeB. Each eNodeB has a static protection subframe. During this time, the other eNodeBs have a static forbidden subframe. For example, the femto eNodeB has a protection subframe (U subframe) of subframe 0 corresponding to a prohibited subframe (N subframe) of subframe 0. Similarly, the macro eNodeB has a protection subframe (U subframe) of subframe 7 corresponding to a prohibited subframe (N subframe) of subframe 7. The subframes 1-6 are dynamically allocated as any one of the protection subframe (AU), the prohibition subframe (AN), and the common subframe (AC). In a common subframe (AC) dynamically allocated in subframes 5 and 6, both femto eNodeB and macro eNodeB may transmit data.

  Since the attacking eNodeB is not intended to transmit unicast traffic, protection subframes (such as U / AU subframes) have reduced interference and high channel quality. . In other words, the attacking eNodeB is not prohibited from transmitting, but intends to reduce interference in protected subframes by avoiding scheduling unicast traffic. Forbidden subframes (eg, N / AN subframes) do not have data transmission, so that the victim eNodeB can transmit data with a low interference level. Common subframes (eg, C / AC subframes) have channel quality that depends on the number of neighboring eNodeBs that are transmitting data. For example, when the neighboring eNodeB is transmitting data in the common subframe, the channel quality of the common subframe may be lower than that of the protection subframe. The channel quality of the common subframe may also be low for the extended boundary area (EBA) that is strongly affected by the attacking eNodeB. The EBA UE not only belongs to the first eNodeB, but can also be located within the effective communication area of the second eNodeB. For example, a UE communicating with a macro eNodeB near the range limit of the femto eNodeB effective communication range is an EBA UE.

  An example of another interference management scheme that may be applied in LTE / -A is slow adaptive interference management. By using this approach for interference management, resources are negotiated and allocated over a time scale much larger than the scheduling interval. The purpose of this scheme is to find all transmit power combinations of the source eNodeB and UE that maximize the overall usability of the network across all time or frequency resources. “Usefulness” may be defined as a function of user data rate, quality of service (QoS) flow delay, and fairness metric. Such an algorithm has central access with access to all information used to solve the optimization and with control over all transmitting entities such as, for example, a network controller (FIG. 1). Can be calculated by the entity. This central entity may not always be realistic or desirable. Thus, in an alternative aspect, a distributed algorithm may be used that determines resource usage based on channel information from a set of nodes. Thus, a slow adaptive interference algorithm can be deployed with a central entity or by distributing the algorithm across various sets of nodes / entities in the network.

  The UE may operate in a dominant interference scenario that may observe high interference from one or more interfering eNodeBs. The dominant interference scenario can be caused by limited association. For example, in FIG. 1, UE 120y may be near femto eNodeB 110y and may have high received power for eNodeB 110y. However, due to constrained relevance, UE 120y cannot access femto eNodeB 110y and instead has macro eNodeB 110c with low received power (as shown in FIG. 1) or similarly low A femto eNodeB 110z (not shown in FIG. 1) with received power may be connected. UE 120y may then observe high interference from femto eNodeB 110y on the downlink and cause high interference to eNodeB 110y on the uplink. When operating in connected mode, UE 120y may experience sufficient interference in dominant interference scenarios where UE 120y can no longer maintain an acceptable connection within eNodeB 110c.

In such dominant interference scenarios, even in a synchronous system, the distance between the UE and multiple eNodeBs can be different, resulting in downlink signal in addition to the signal power mismatch observed at the UE. Can also be observed by the UE. The eNodeBs in the synchronization system are synchronized based on estimates beyond the system. However, considering a UE at a distance of 5 km from the macro eNodeB, for example, the propagation delay of the downlink signal received from the macro eNodeB is about 16.67 microseconds (5 km ÷ 3 × 10 ⁸ , ie , The speed of light 'c') will be delayed. When the downlink signal from the macro eNodeB is compared with the downlink signal from the closer femto eNodeB, the timing difference can approach the level of time-to-live (TLL) error.

  Furthermore, this timing difference can adversely affect interference cancellation at the UE. Interference cancellation often uses cross-correlation properties between combinations of multiple versions of the same signal. By combining multiple copies of the same signal, interference can be more easily identified. This is because the interference will not be in the same place while there will be interference in each copy of the signal. Using the cross-correlation of the combined signals, the actual signal portion can be determined and distinguished from interference. As a result, interference is removed.

  The dominant interference scenario can also be caused by range expansion. If the UE connects to an eNodeB with low path loss and low SNR (signal to noise ratio) among all eNodeBs detected by the UE, range expansion may occur. For example, in FIG. 1, the UE 120x may detect the macro eNodeB 110b and the pico eNodeB 110x. Further, the UE has lower received power for eNodeB 110x than for eNodeB 110b. If the path loss of eNode B 110x is lower than the path loss of macro eNode B 110b, UE 120x may connect to pico eNode B 110x. As a result, for UE 120x, for a given data rate, interference to the wireless network may be low.

  In range-capable wireless networks, enhanced inter-cell interference coordination (eICIC) allows the UE to operate in the presence of macro base stations with strong downlink signal strength (eg, pico base stations, femto Service from a base station, relay, etc., and the UE can obtain service from a macro base station in the presence of strong interference signals from base stations that the UE is not allowed to connect to become able to. As described above, eICIC can be used to coordinate resources. This allows the interfering base station to give up some resources and enable control and data transmission between the UE and the serving base station. If the network supports eICIC, the base station may negotiate and coordinate resource usage to reduce and / or eliminate interference from interfering cells that have abandoned some of the resources. Thus, the UE can access the serving cell even with severe interference by using resources abandoned by the interfering cell.

  For UEs that support eICIC, existing criteria for analyzing radio link failure conditions may not satisfactorily address the conditions of the coordination cell. In general, when a UE declares a radio link failure, the UE disconnects from this base station and searches for a new base station. If the UE is in the area of severe interference where interference is coordinated between base stations by the interfering cell that abandons some of the resources, the UE measurement of signal to noise ratio (SNR) or PDCCH decoding error rate is Depending on whether the measured resource is abandoned by the interfering cell, it can vary considerably. If the UE measures the PDCCH decoding error rate or SNR of resources that were not abandoned by the interfering cell, the UE may access the serving cell using the resources abandoned by the interfering cell, Due to high interference, RLF can be declared erroneously.

  FIG. 6 is a block diagram conceptually illustrating a macro cell 601 in a wireless network 630 configured in accordance with one aspect of the present disclosure. Wireless network 630 is a heterogeneous network in which macro cell 601 is served by macro base station 600. Two additional cells, the femto cell 603 served by the femto base station 602 and the pico cell 606 served by the pico base station 605, are the coverage area of the macro cell 601. It is overlaid in. Although only the macro cell 601 is illustrated in FIG. 6, the wireless network 630 may include a plurality of macro cells similar to the macro cell 601.

  UE 604 is located in macro cell 601 or also in femto cell 603. Communication with the femto base station 602 in the femto cell 603 is only available for authorized UEs. In this example, the UE 604 is not allowed to communicate via the femto base station 602. Therefore, UE 604 maintains communication with macro base station 600. When the UE 604 enters the femto cell 603, the interference caused by the femto base station 602 by the interference signal 608 affects the signal quality of the communication signal 609 between the UE 604 and the macro base station 600. When the interference level increases, the UE 604 that supports eICIC identifies resources that the femto base station 602 abandons based on interference coordination with the macro base station 600. Abandoned resources may be defined as time domain resources, frequency domain resources, or even a combination of time domain and frequency domain resources. If the abandoned resource is time-based, the interfering base station 602 does not use some of the time-domain accessible subframes as described above with reference to FIG. If the abandoned resource is frequency based, the interfering base station 602 does not use some of the subcarriers accessible in the frequency domain. If the abandoned resource is a combination of both frequency and time, the interfering base station 602 does not use the resource defined by the frequency and time.

  Once the abandoned resource is identified, the UE 604 obtains the signal quality of the abandoned resource. For example, the signal quality can be obtained by the error rate of the abandoned resource PDCCH (Physical Downlink Control Channel). The signal quality information includes various errors including decoding the PDCCH, calculating the error rate from the decoded signal, or predicting the error rate from the estimated SNR (signal-to-noise ratio) of the PDCCH. Can be obtained by UE 604 by rate analysis. In one aspect, the measurement is channel state information (CSI), including but not limited to channel quality indicator (CQI) measurement, precoding matrix indicator (PMI) measurement, or rank indicator (RI) measurement. is there. If the PDCCH error rate in the abandoned resource exceeds a predetermined error rate level, the UE 604 will declare a radio link failure and terminate the signaling connection to the macro base station 600. In one example, a radio link failure is declared when the error rate reflects an unacceptably high value and the abandoned resource cannot adequately support the communication signal. If the error rate of the abandoned resource does not exceed a predetermined level (eg, a level that allows the abandoned resource to properly support the communication signal), the UE 604 may have abandoned the femto base station 602. Access to the macro base station 600 may be continued using the resources.

  In another example, the UE 604 identifies and removes interference from the common management signal transmitted by the femto base station 602 with the abandoned resource before obtaining the PDCCH error rate in the abandoned resource. sell. In accordance with the eICIC management protocol, even if the femto base station 602 relinquishes resources, the femto base station 602 can simply clear and relinquish the data slot of the abandoned subframe. The femto base station 602 may include common E-UTRAN systems, common reference signals (CRS), PDCCH / PCFICH for broadcast signaling support, system information block (SIB) messages, paging messages, etc. Maintain a management slot for transmitting management signals. In one example, prior to determining signal quality and obtaining error rate levels, UE 604 may identify such generic management signals and remove interference that may be due to these signals.

  In another example, the UE 604 identifies which resources have been abandoned before obtaining the PDCCH error rate for the abandoned resources. Various methods can be implemented to identify abandoned resources. In one example, the UE 604 receives a setup signal identifying the abandoned resource from the macro base station 600 that is its serving base station. This configuration signal may be of various types such as dedicated signaling (eg, radio resource control (RRC) message), broadcast message (eg, system information block (SIB) message) overhead message, etc. It can be any of the system messages. This configuration information received from the serving base station uses, for example, the range of physical base station identification information or the class of base station power, which of the UEs 604 to determine which base station is the problem. Thus, information such as which resources abandoned are available to obtain the PDCCH error rate.

  In the alternative, UE 604 receives the overhead message sent by the interfering base station (eg, femto base station 602) rather than receiving the message from macro base station 600 and is abandoned. Identify the resource When the femto base station 602 relinquishes a particular resource in accordance with the eICIC protocol, the femto base station 602 broadcasts or transmits an overhead message to any of the clients to identify the particular resource being relinquished. In one example, the UE 604 interprets such an overhead signal and reads which resources are being abandoned.

  In another example, abandoned resources are set up with a limited usage pattern for the femto base station 602. Furthermore, in such an alternative, the eICIC protocol instructs the femto base station 602 to periodically limit the use of any particular abandoned resource. During the period of limited use, the femto base station 602 clears and abandons the data slot of the abandoned subframe and clears all other resources in the abandoned subframe, including the reference signal. And give up. That is, the femto base station 602 does not transmit any general management signals with abandoned resources. Various period lengths may be defined such that the femto base station 602 does not use abandoned resources for a defined period length. In one example, the defined duration is in milliseconds (ms) (eg, every 8 milliseconds, every 10 milliseconds, every 40 milliseconds, etc.). In such an aspect, the UE 604 obtains the PDCCH error rate for a limited period of use and does not listen to any general management signal for further interference cancellation. In one aspect, the periodic resource is a multimedia broadcast over a single frequency network (MBSFN) subframe, so the UE 604 does not remove any general management signals.

  UE 607 is located in macro cell 601 and also in pico cell 606. According to the range extension function of the LTE-A radio network 630, the cell load is leveled by connecting the UE 607 to the pico base station 605 for communication. However, the power level of the communication signal 611 between the UE and the pico base station 605 is lower than the power level of the interference signal 610 transmitted from the macro base station 600. The interference caused by the interference signal 610 prompts the UE 607 to begin analysis on radio link failure. The UE 607 identifies an abandoned resource from the macro base station 600 that is an interference source base station. In one example, UE 607 may identify abandoned resources from setup / release messages transmitted from a serving cell (eg, pico base station 605). This message may also include a range of physical base station identification information or class of base station power, or other information regarding the clearing and abandoned resources of the interfering base station. As illustrated, the pico cell 606 overlaps the macro cell 601. Accordingly, the pico base station 605 includes information identifying the abandoned resources of the macro base station 600 to perform the range extension function. It is effective that the pico base station 605 transmits this information. In particular, in one aspect, the pico base station is the dominant transmitter and may more easily provide this information to the UE. Upon identifying the indicated abandoned resources, UE 607 may obtain the signal quality of the abandoned resources, for example, by obtaining the PDCCH error rate in these abandoned resources. Based on the error rate level, the UE 607 determines whether to declare radio link failure (RLF).

  In one example, a particular set of time domain resources (eg, subframes) and / or frequency domain resource blocks (RBs) are designated as abandoned resources. These resources may include a set of frequency and / or subframe resource blocks that exclude PDCCH regions. This particular set of resources (eg, subframes) is measured to determine radio link failure.

  In another aspect, a new control channel is defined that was originally part of the data channel. The UE uses this new control channel (R-PDCCH) to obtain an error rate for radio link failure determination. For example, considering a wireless network 630 as illustrated in FIG. 6, if UE 604 detects sufficient interference from interference signal 608 to trigger radio link failure analysis, UE 604 may subframe and / or Alternatively, resource identification information identifying a set of frequency resource blocks (RBs) is acquired. If the set of subframes and / or frequency resource blocks excludes the PDCCH region, the UE 604 does not perform error rate calculation for the PDCCH. Instead, the UE 604 obtains the abandoned resource signal quality in another manner (eg, using R-PDCCH to obtain the error rate). If a set of subframes designated as abandoned resources is defined in the time and frequency domains, and this set is a subset of the interfering cell's MBSFN subframes, the resource block location is It is configured to avoid collisions with the frequency domain control / data channel of the cell (ie, macro base station 600).

  FIG. 7 illustrates a method 700 for determining radio link failure (RLF) using enhanced interference coordination and cancellation. At block 702, the UE detects interference from an interfering base station in the network that supports enhanced interference coordination and cancellation (eICIC). In block 704, the UE receives a message identifying the abandoned resources of the interfering base station. In block 706, the UE determines the signal quality of the abandoned resource. In block 708, the UE determines whether the signal quality exceeds a predetermined threshold. Based on this determination, control flow moves to block 710 where the UE declares a radio link failure (RLF). Alternatively, the UE may maintain association with the serving cell at block 712.

  In one configuration, UE 120 including means for detecting interference is configured for wireless communication. In one aspect, the means for detecting includes antennas 452a-45r, demodulators 454a-454r, receive processor 458, controller / processor 480, and / or configured to perform the functions detailed by the means for selecting. There may be a memory 482. UE 120 is also configured to include means for receiving a message. In one aspect, the means for receiving is an antenna 452a-45r, a demodulator 454a-454r, a receiver processor 458, a controller / processor 480, and / or configured to perform the functions detailed by the means for transmitting. There may be a memory 482. UE 120 is also configured to include means for determining signal quality. In one aspect, the means for determining can be a controller / processor 480 and a memory 482 configured to perform the functions detailed by the means for measuring. UE 120 is also configured to include means for declaring a radio link failure. In one aspect, the means for declaring may be memory 482 and controller / processor 480 configured to perform the functions detailed by the declaring means. In another aspect, the means described above may be a module or any device configured to perform the functions described by the means described above.

  Those skilled in the art will further recognize that the various exemplary logic blocks, modules, circuits, and algorithm steps described in connection with the disclosure herein are electronic hardware, computer software, or combinations thereof. Will be realized as: To clearly illustrate the interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps have been generally described in terms of their functionality. Whether these functions are implemented as hardware or software depends on the particular application and design constraints imposed on the overall system. Those skilled in the art can implement the functions described above in a manner that varies with each particular application. However, this application judgment should not be construed as causing a departure from the scope of the present invention.

  Various exemplary logic blocks, modules, and circuits described in connection with the disclosure herein are general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gates. Implemented using an array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of the above designed to implement the functions described above Can be implemented. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or sequential circuit. The processor may be implemented, for example, as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors associated with a DSP core, or any other such combination of computing devices. Can be done.

  The method or algorithm steps described in connection with the disclosure herein may be implemented directly in hardware, in software modules executed by a processor, or in a combination of the two. The software module may be RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or other types of storage media known in the art. Can exist. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and storage medium can reside in the ASIC. The ASIC may exist in the user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.

  In one or more exemplary designs, the functions described may be implemented by hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media. These include any medium that facilitates transfer of a computer program from one location to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer readable media can be RAM, ROM, EEPROM, CD-ROM or other optical disk storage device, magnetic disk storage device or other magnetic storage device, or instructions or data. Any other medium may be provided that is used to transmit or store the desired program code means in the form of a structure and that may be accessed by a general purpose or special purpose computer, or a general purpose or special purpose processor. In addition, any connection is properly referred to as a computer-readable medium. Coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or from websites, servers, or other remote sources using wireless technologies such as infrared, wireless and microwave When software is transmitted, coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, wireless and microwave are included in the definition of the medium. The discs (disk and disc) used in this specification are compact disc (disc) (CD), laser disc (registered trademark) (disc), optical disc (disc), and digital versatile disc (disc) (DVD). ), Floppy disk (disk), and blue ray disk (disc). These discs optically reproduce data using a laser. In contrast, a disk normally reproduces data magnetically. Combinations of the above should also be included within the scope of computer-readable media.

  The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. As such, the present disclosure is not intended to be limited to the examples and designs presented herein, but represents the broadest scope consistent with the principles and novel features disclosed herein. It is said that.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. As such, the present disclosure is not intended to be limited to the examples and designs presented herein, but represents the broadest scope consistent with the principles and novel features disclosed herein. It is said that.
The invention described in the scope of the claims at the time of filing is added below.
[Invention 1]
A wireless communication method,
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Detecting interference from the original base station;
Receiving a dedicated message identifying the abandoned resource from the interfering base station;
Determining the signal quality of the abandoned resource;
Declaring radio link failure if the determined signal quality satisfies a predetermined threshold;
A method comprising:
[Invention 2]
Determining the signal quality further includes
Receiving a general management signal transmitted by the interfering base station;
Removing interference in the abandoned resource due to the general management signal;
A method according to invention 1, comprising:
[Invention 3]
The method of claim 1, wherein the dedicated message is a radio resource control (RRC) message.
[Invention 4]
The method according to claim 2, wherein the dedicated message is at least one of a connection setup message, a connection reconfiguration message, and a connection reestablishment message.
[Invention 5]
Receiving from the serving base station an indication indicating the interfering base station;
The indication comprises at least one of a range of base station identification information and a class of base station power,
The method according to invention 1.
[Invention 6]
The abandoned resource is configured using periodic subframes in which the interfering base station is restricted from transmitting,
During the periodic subframe, user equipment (UE) determines the signal quality;
The method according to invention 1.
[Invention 7]
The abandoned resource is
A first partition having a subset of subframes broadcast from the interfering base station;
A second segment configured to avoid collision with a frequency domain channel of the serving base station;
A method according to invention 1, comprising:
[Invention 8]
A wireless communication method,
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Detecting interference from the original base station;
Receiving a message identifying the abandoned resource from the interfering base station, wherein the message is transmitted from the serving base station and indicating the abandoned resource; and At least one of an overhead message transmitted from an interfering base station and indicating the abandoned resource;
Determining the signal quality of the abandoned resource;
Declaring radio link failure if the determined signal quality satisfies a predetermined threshold;
A method comprising:
[Invention 9]
A device for wireless communication,
Memory,
And at least one processor connected to the memory,
The at least one processor comprises:
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Detect the interference from the original base station,
Receiving a dedicated message identifying the abandoned resource from the interfering base station;
Determine the signal quality of the abandoned resource;
Declare radio link failure if the determined signal quality meets a predetermined threshold
Configured as follows.
[Invention 10]
The processor further includes:
Receiving a general management signal transmitted by the interfering base station;
Remove interference in the abandoned resource due to the general management signal
An apparatus according to invention 9, configured as described above.
[Invention 11]
The apparatus according to claim 9, wherein the dedicated message is a radio resource control (RRC) message.
[Invention 12]
The apparatus according to claim 9, wherein the dedicated message is a setup and release message.
[Invention 13]
The processor further includes:
Configured to receive an indication indicating the base station of the interference from the serving base station;
The indication comprises at least one of a range of base station identification information and a class of base station power,
The device according to invention 9.
[Invention 14]
The abandoned resource is configured using periodic subframes in which the interfering base station is restricted from transmitting,
During the periodic subframe, user equipment (UE) determines the signal quality;
The device according to invention 9.
[Invention 15]
The abandoned resource is
A first partition having a subset of subframes broadcast from the interfering base station;
A second segment configured to avoid collision with a frequency domain channel of the serving base station;
An apparatus according to invention 9, comprising:
[Invention 16]
A device for wireless communication,
Memory,
And at least one processor connected to the memory,
The at least one processor comprises:
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Detect the interference from the original base station,
A message identifying the abandoned resource is received from the interfering base station, wherein the message is transmitted from the serving base station and indicating the abandoned resource and the interference At least one of an overhead message transmitted from the original base station and indicating the abandoned resource;
Determine the signal quality of the abandoned resource;
Declare radio link failure if the determined signal quality meets a predetermined threshold
Configured as follows.
[Invention 17]
A computer program product for wireless communication in a wireless network, comprising:
Comprising a computer readable medium having recorded non-transitory program code, the program code comprising:
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Program code to detect interference from the original base station;
Program code for receiving a dedicated message identifying the abandoned resource from the interfering base station;
Program code for determining the signal quality of the abandoned resource;
A program code for declaring a radio link failure if the determined signal quality satisfies a predetermined threshold;
A computer program product.
[Invention 18]
A computer program product for wireless communication in a wireless network, comprising:
A computer readable medium having recorded program code, the program code comprising:
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Program code to detect interference from the original base station;
A program code for receiving a message identifying the abandoned resource from the interfering base station, wherein the message is transmitted from the serving base station and broadcast indicating the abandoned resource At least one of a message and an overhead message transmitted from the interfering base station and indicating the abandoned resource;
Program code for determining the signal quality of the abandoned resource;
A program code for declaring a radio link failure if the determined signal quality satisfies a predetermined threshold;
A computer program product comprising
[Invention 19]
A device for wireless communication,
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Means for detecting interference from the original base station;
Means for receiving a dedicated message identifying the abandoned resource from the interfering base station;
Means for determining the signal quality of the abandoned resource;
Means for declaring a radio link failure if the determined signal quality satisfies a predetermined threshold;
A device comprising:
[Invention 20]
A device for wireless communication,
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Means for detecting interference from the original base station;
Means for receiving a message identifying the abandoned resource from the interfering base station, wherein the message is transmitted from the serving base station and indicating abandoned resource; and An overhead message transmitted from the interfering base station and indicating the abandoned resource;
Means for determining the signal quality of the abandoned resource;
Means for declaring a radio link failure if the determined signal quality satisfies a predetermined threshold;
A device comprising:

Claims (20)

A wireless communication method,
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Detecting interference from the original base station;
Receiving a dedicated message identifying the abandoned resource from the interfering base station;
Determining the signal quality of the abandoned resource;
Declaring radio link failure if the determined signal quality satisfies a predetermined threshold;
A method comprising: Determining the signal quality further includes
Receiving a general management signal transmitted by the interfering base station;
2. The method of claim 1, comprising removing interference in the abandoned resource due to the general management signal.   The method of claim 1, wherein the dedicated message is a radio resource control (RRC) message.   The method of claim 2, wherein the dedicated message is at least one of a connection setup message, a connection reconfiguration message, and a connection reestablishment message. Receiving from the serving base station an indication indicating the interfering base station;
The indication comprises at least one of a range of base station identification information and a class of base station power,
The method of claim 1. The abandoned resource is configured using periodic subframes in which the interfering base station is restricted from transmitting,
During the periodic subframe, user equipment (UE) determines the signal quality;
The method of claim 1. The abandoned resource is
A first partition having a subset of subframes broadcast from the interfering base station;
The method of claim 1, comprising: a second partition configured to avoid collision with a frequency domain channel of the serving base station. A wireless communication method,
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Detecting interference from the original base station;
Receiving a message identifying the abandoned resource from the interfering base station, wherein the message is transmitted from the serving base station and indicating the abandoned resource; and At least one of an overhead message transmitted from an interfering base station and indicating the abandoned resource;
Determining the signal quality of the abandoned resource;
Declaring radio link failure if the determined signal quality satisfies a predetermined threshold;
A method comprising: A device for wireless communication,
Memory,
And at least one processor connected to the memory,
The at least one processor comprises:
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Detect the interference from the original base station,
Receiving a dedicated message identifying the abandoned resource from the interfering base station;
Determine the signal quality of the abandoned resource;
An apparatus configured to declare a radio link failure if the determined signal quality satisfies a predetermined threshold. The processor further includes:
Receiving a general management signal transmitted by the interfering base station;
The apparatus of claim 9, configured to cancel interference in the abandoned resource due to the general management signal.   The apparatus of claim 9, wherein the dedicated message is a radio resource control (RRC) message.   The apparatus of claim 9, wherein the dedicated message is a setup and release message. The processor further includes:
Configured to receive an indication indicating the base station of the interference from the serving base station;
The indication comprises at least one of a range of base station identification information and a class of base station power,
The apparatus according to claim 9. The abandoned resource is configured using periodic subframes in which the interfering base station is restricted from transmitting,
During the periodic subframe, user equipment (UE) determines the signal quality;
The apparatus according to claim 9. The abandoned resource is
A first partition having a subset of subframes broadcast from the interfering base station;
10. The apparatus of claim 9, comprising a second partition configured to avoid collision with a frequency domain channel of the serving base station. A device for wireless communication,
Memory,
And at least one processor connected to the memory,
The at least one processor comprises:
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Detect the interference from the original base station,
A message identifying the abandoned resource is received from the interfering base station, wherein the message is transmitted from the serving base station and indicating the abandoned resource and the interference At least one of an overhead message transmitted from the original base station and indicating the abandoned resource;
Determine the signal quality of the abandoned resource;
An apparatus configured to declare a radio link failure if the determined signal quality satisfies a predetermined threshold. A computer program product for wireless communication in a wireless network, comprising:
Comprising a computer readable medium having recorded non-transitory program code, the program code comprising:
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Program code to detect interference from the original base station;
Program code for receiving a dedicated message identifying the abandoned resource from the interfering base station;
Program code for determining the signal quality of the abandoned resource;
A computer program product comprising a program code for declaring a radio link failure if the determined signal quality satisfies a predetermined threshold. A computer program product for wireless communication in a wireless network, comprising:
A computer readable medium having recorded program code, the program code comprising:
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Program code to detect interference from the original base station;
A program code for receiving a message identifying the abandoned resource from the interfering base station, wherein the message is transmitted from the serving base station and broadcast indicating the abandoned resource At least one of a message and an overhead message transmitted from the interfering base station and indicating the abandoned resource;
Program code for determining the signal quality of the abandoned resource;
A computer program product comprising: program code for declaring a radio link failure if the determined signal quality satisfies a predetermined threshold; A device for wireless communication,
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Means for detecting interference from the original base station;
Means for receiving a dedicated message identifying the abandoned resource from the interfering base station;
Means for determining the signal quality of the abandoned resource;
Means for declaring a radio link failure if the determined signal quality satisfies a predetermined threshold;
A device comprising: A device for wireless communication,
In a network that supports an interference coordination and cancellation mechanism that includes abandonment of at least one radio transmission resource and allocation of the abandoned at least one radio transmission resource from a base station from which interference is provided to a serving base station, the interference Means for detecting interference from the original base station;
Means for receiving a message identifying the abandoned resource from the interfering base station, wherein the message is transmitted from the serving base station and indicating abandoned resource; and An overhead message transmitted from the interfering base station and indicating the abandoned resource;
Means for determining the signal quality of the abandoned resource;
Means for declaring a radio link failure if the determined signal quality satisfies a predetermined threshold;
A device comprising:

Images